The structure and properties of cellulose acetate (CA) prepared by homogeneous acetylation in ionic liquids (CAHomo) and heterogeneous acetylation (CAHete) were investigated.The characterizations of CAs such as molecular weight

molecular weight distribution

degree of substitution (DS)

distribution of acetyl groups and the partial DS at C-2

C-3 and C-6 were determined by GPC

1H- and 13C-NMR.The DS of CAHomo and CAHete was about 2.50 calculated by 1H-NMR.The distribution of acetyl groups calculated by 13C-NMR was C-6 C-3 C-2 for CAHomo and C-3 C-2 C-6 for CAHete

respectively.In addition

the structure of CAHomo had better uniformity than that of CAHete.Subsequent property studies showed that the chemical structure differences of CAs had tiny effect on their properties

such as crystallinity

solubility and thermal properties.CAHomo and CAHete were all amorphous structure

and they had better solubility in polar organic solvents.The glass transition temperature and thermal stability were similar for these CAs samples.Therefore

CAHomo synthesized by homogeneous acetylation in ionic liquids had similar physical properties as those of CAHete prepared by heterogeneous acetylation

but the structure of CAHomo had better uniformity than that of CAHete.